In the sixth installment of the bestselling alternate history series, Caesar's ploy to keep his Legions under control and moving east from the Ganges by introducing his men to the riches of the Han Empire initially succeeds in ending what is now the second mutiny of his army. This success proves to be short-lived when, just a few months later, while cutting a path through the impenetrable jungle across the modern Indochinese Peninsula that the men have dubbed "The Green Hades," there's a third mutiny, the most violent to date that results in the slaying of several Centurions, including the Primus Pilus of the 8th Legion, and the men refusing to move another mile. Faced with another existential threat to his dream, the greatest general of his age once again manages to avert disaster, although it's at the cost of several months of progress as the army stays in place less than halfway across the peninsula. Nevertheless, they do manage to reunite with the fleet, which has traveled the waterborne route around both the Malay and Indochina Peninsula, meeting on the eastern coast of modern Vietnam. The arrival of Caesar's army and fleet in the southern reach of his Empire finally stirs Emperor Yuan of the Han, prompting him to send an emissary, Zhang Meng, in the first meeting between the two superpowers of the ancient world. Yuan already has his hands full, both with Zhizhi the leader of the Xiongnu, a nomadic tribe that is intent on wresting territory along the western edge of the Han Empire, factionalism within his own court, and a rebellious general, Xao, on the island of Zhuya, modern day Hainan. It is with this in mind that, from a proposal by young Zhang, the Han and Rome cooperate; in exchange for Caesar and his Legions invading Zhuya and defeating Xao's army, the Han Emperor will provide enough food to feed their massive army for a year, and the Romans will be allowed to occupy the island. As usually happens, it's Sextus Scribonius who divines the truth, that the proposal that supposedly came from Emperor Yuan and the Han is actually Caesar's own idea, having manipulated the talented but inexperienced Zhang into presenting it to his Emperor as his own idea. What will happen when Emperor Yuan discovers that he's been manipulated?